Ancient history of Lebanon The coastal plain of Lebanon is the historic home of a string of coastal trading cities of Semitic culture, which the Greeks termed Phoenicia, whose maritime culture flourished there for more than 2,000 years (c. 2700450 BCE). Ancient ruins in Byblos, Berytus (Beirut), Sidon, Sarepta, and Tyre show a civilized nation, with urban centers and sophisticated arts. Present-day Lebanon was a cosmopolitan centre for many nations and cultures. Its people roamed the Mediterranean seas, skilled in trade and in art, and founded trading colonies. They were also the creators of the oldest known 24-letter alphabet, a shortening of earlier 30-letter alphabets such as Proto-Sinaitic and Ugaritic. Phoenicia maintained an uneasy tributary relationship with the neo-Assyrian and neo-Babylonian empires; it was conquered outright by the Achaemenid dynasty of Persia, which organized it as a satrapy. It was added to the empire of Alexander the Great, who notably conquered Tyre (332 BCE) by extending a still-extant causeway from the mainland in a seven-month effort. It fell to the Seleucid Empire after Alexander's death. The area was conquered by the Roman Empire in the first century BC and remained Roman until the advent of the Caliphate. Christianity was introduced to Phoenicia from neighboring Galilee soon after the time of Jesus of Nazareth; the Arab advances brought Islam soon after the death of Islam's Prophet Muhammad. Muslim influence increased greatly in the seventh century when the Umayyad capital was established at nearby Damascus.